Poetry Publication, bringing it together

I am starting to struggle with this brief, I am having difficulty with the cover and fold posters. I think that the fold out poster and the cover should link in some way, as it would help explore the possible imagery for the cover and also give the cover's design a purpose.

After messing around with type/layout/typeface etc... I am at a stage now that I think I could expand from:

Each issue is going to be colour themed, I also want to covers/posters to relate slightly to the content of the publication. Therefore I need something that isn't too 'arty' but more restricted/calm.